1. Field of the Invention
The present invention relates generally to door locks, and more particularly to a door lock apparatus having a novel mounting arrangement wherein the mainframe structure of the apparatus is employed as part of the securing means thereof.
1. Description of the Prior Art
As is well known in the art, various problems and difficulties are encountered in providing a suitable door lock device that allows one to readily change a door lock mounted in a door in a very efficient manner and with ease, without the need of assembling the lock device or the need of serveral tools for mounting same.
Many types of door locks are in use today, each having its particular design and mounting arrangement. For this reason, it becomes a problem when there is a need to repeatedly change door locks, as is often the case in large rental complexes. Most known door locks do not lend themselves to such operations since these devices have various limitations that restrict their use under such conditions. Often they are complicated in structure and thus are time consuming to install. Moreover, the average lock unit is not only expensive but costly to maintain as well.
In the past, door locks (excluding striker assemblies) have come in four parts: latch or bolt assembly; exterior cylinder assembly, which is designed to receive a key; latch operation knob or the handle mounted on the interior of the door; and mounting screws designed to secure individual parts to the door. Thus, to accommodate these parts, the material must be removed from the door by drilling, chiseling, or cutting.
When a lock has an externally mounted cylinder, it requires the changing of all the individual parts. That is, the lock must be disassembled and new parts reinstalled. This is time-comsuming, costly, and requires a degree of skill that is not common to the average manager or homeowner. The need for security in our crime-ridden society has prompted many cities to establish statutes that require owners of rental units to change locks every time an old tenant moves out or a new tenant moves in. If a master key for a large apartment complex falls into the wrong hands, every lock on the property must be changed or remastered.
The following are patent references cited in the original filed application.
U.S. Pat. No. 640,217 to Moore PA1 U.S. Pat. No. 926,336 to Keil PA1 U.S. Pat. No. 2,200,387 to Erath PA1 U.S. Pat. No. 3,673,605 to Allenbaugh PA1 889,738 Canada PA1 U.S. Pat. No. 898,748 to Keil PA1 U.S. Pat. No. 1,483,333 to Capece PA1 261,865 Great Britain PA1 2,415,709 France
U.S. Pat. No. 3,257,136 to Russell et al